Kamitsis had become a “test case” for an investigation known as Operation Subutai, which was looking into 27 travel agents suspected of defrauding the NT Health Department’s pensioner travel concession scheme.

Thousands of text messages were downloaded from Kamitsis’ phone, revealing a sexual relationship between the pair from at least 2012 until the month before her arrest in November 2014.

McRoberts had known about the potential arrest of Kamitsis from at least May 2014.

At the time McRoberts told senior officers he knew Kamitsis “socially,” that they were “friends” who saw each other at Crime Stoppers NT functions, that there wasn’t a conflict of interest.

Kamitsis was the Crime Stoppers NT chairwoman in 2014.

“We’re probably going to lock her up,” then assistant commissioner Reece Kershaw told him during a briefing, a comment he said was designed to test McRoberts’ reaction.

“If she has to be charged, she has to be charged,” McRoberts replied, which Mr Kershaw said reassured him.

Then acting superintendent of crime Clinton Sims described McRoberts as “irate” during a meeting in late June, where senior officers were “being told” the matter was “more of a civil nature than a criminal nature”.

McRoberts again assured his colleagues he wasn’t conflicted.

A few days later McRoberts briefed then chief minister Adam Giles, then health minister Robyn Lambley and then NT Health Department chief executive Len Notaras on the investigation.

They agreed to set up an inter-agency taskforce to oversee the alternative civil strategy, despite Mr Giles making it clear he wanted to “go hard” on the travel agents.

“It was extraordinary for me because I’d never been involved in anything like that before, where you have 27 businesses possibly defrauding the Government,” Ms Lambley told the court.